1. Field of the Invention
The present invention relates to a processing device and a processing method for a substrate such as a semiconductor substrate.
2. Description of the Related Art
A method using a dicing saw which is rotated at a high speed is widely used as a method of applying some process, for example, dividing to a substrate such as a semiconductor substrate. According to this method, a substrate in a state of being adhered on an adhesive sheet is cut by a dicing saw made of a diamond blade, etc.
There is a kind of semiconductor element called MEMS (Micro Electro Mechanical System) element. The MEMS element comprises a mechanical structure which is formed on a surface of a semiconductor substrate in which circuit elements are formed. The MEMS element is used for an electronic component and a mechanical component necessary for many types of electronic systems and electronic optical systems. For example, an optical switching element having a movable cantilever can be cited as the MEMS element.
In the process of manufacturing a component comprising the MEMS element, a chip (die) of the MEMS element is cut out from a substrate by the above-described method, likewise a substrate of an ordinary element. However, a mechanical structure is exposed on the surface of the MEMS element substrate, and this causes the following problems if the above-described conventional processing method is used.
First, in case of a cutting process using a dicing saw, minute cutting dust produced from cutting stick to the mechanical structure, causing a fear that the function of the mechanical structure might be damaged. For example, if minute cutting dust enter a space between a cantilever and the surface of a substrate, the switching function of a switching element might be harmed.
Second, in order to prevent cutting dust from sticking and a substrate from being overheated, pure water is supplied, in the cutting process, to where the substrate and a dicing blade contact each other and therearound. Because of this, the mechanical structure, which is exposed on the surface of the substrate might be damaged by the flow of the water.
Third, the function of the mechanical structure might be damaged by the surface tension of the water when the water evaporates. For example, if a cantilever is stuck on the surface of a substrate, the switching function of a switching element might be damaged.
As described above, in a case where a substrate on which an MEMS element is formed is processed by utilizing the above-described conventional method, there is a danger that the mechanical structure exposed on the surface of the substrate and its function might be damaged. This might damage the reliability of substrate processing, and cause a decrease in the yield.
Problems similar to those described above happen not only when processing an MEMS element substrate, but also applying a process such as cutting to a substrate on whose surface a fine structure is formed.